ArrowStringArray: delay/conditionally import pyarrow.compute

[jorisvandenbossche]

We currently check if pyarrow is available (and a sufficiently recent version), and if that's the case, simply import pyarrow.compute:

pandas/pandas/core/arrays/string_arrow.py

Lines 63 to 65 in 3fe8e24

	if not pa_version_under1p0:
	import pyarrow as pa
	import pyarrow.compute as pc

However, in theory, it is possible to have a pyarrow installation without pyarrow.compute support (it's an optional component when building). In that case the import pyarrow.compute as pc import will fail giving a slightly confusing error message + it will fail on a basic import of pandas (even without using any pyarrow functionality).

[jreback]

can u give a specific example where this happens? for all of the string functions we have min required checks AFAICT

[simonjayhawkins]

The ArrowStringArray relies heavily on pyarrow.compute. better to raise than to delay/conditionally import?

[simonjayhawkins]

we changed this in #41732

[jbrockmendel]

is this still relevant now that ArrowDtype is in place? Or more specifically, wouldn't delaying this be much more invasive?